When manufacturing stators having a stator core on which are mounted terminal boards with terminal-receiving receptacles having slots in which the lead wires are to be placed, it has become a common practice to position a stator at a lead connect station and, using a robot end effector, to manipulate the stator coil lead wires to insert them into the receptacle slots. The lead wires, which extend substantially axially of the stator core are bent to extend essentially radially of the stator core when they are inserted into the receptacle slots. Each lead wire is thereby bent at an essentially right angle over a sharp corner at the bottom of a receptacle slot.
The wire at the bending point is under considerable tension because the grip on the end effector against the wire must be sufficiently secure that the lead wire is invariably pulled completely down to the bottoms of the receptacle slots. The sharp bend and tension creates a weakened spot in the lead wire. These factors may be exacerbated when the terminal is inserted into the receptacle. As a result, there is an increased potential for the lead wire to break at this point, especially when the stator is exposed to substantial vibrations during use, such as in a power tool.
In order to overcome the weakness in a lead wire at the point it enters the receptacle, it has been suggested that the stator be so manufactured that the segment of each lead wire extending from the coil to its associated receptacle be made somewhat slack in order to decrease the tension on the wire where it enters the receptacle. So far as known, a satisfactory method and apparatus for providing slackened lead wires have not been developed. The task is not easy because any such method and apparatus, to be satisfactory for use in a mass production manufacturing environment, must be rugged, reliable, and so fast acting that it will not significantly increase the time needed to manufacture the stator.